An example which approaches much more nearly the unmistakable Three-Part song, may be found in Mozart, sonata No.

12, _Menuetto_:-- _Part I_, section one (embryo of a principal theme), measures 1-10, period, extended; section two (embryo of a subordinate theme) measures 11-18, period, _in different key_.
_Part II_, group of three phrases, measures 19-30.
_Part III_, section one, as before, measures 31-40; section two, as before, _but in the principal key_, measures 41-48.
This is, of course, a Three-Part Song-form; but the essential features of the Sonata-allegro are unquestionably present, in miniature.
See also, Beethoven, sonata, op.

101, first movement; certainly a sonata-allegro design, but diminutive.
* * * * * * The superiority of the sonata-allegro form over all other musical designs, is amply vindicated by the breadth of its thematic basis, the straightforwardness and continuity of its structural purpose, the perfection of its thematic arrangement, and the unexcelled provision which it affords for unity, contrast, corroboration, balance, and whatever else a thoroughly satisfactory structural design seems to demand.

Hence, while brief triumphs of apparent "originality" may be achieved by simply running counter to this and similar designs, it seems scarcely possible that any musical form could be contrived that would surpass the sonata-allegro, the last and highest of the forms of composition.
LESSON 17 .-- Analyze the following examples, as usual, carefully defining all the details of the form, according to the general plan adopted in our text:-- Beethoven, pianoforte sonatas; op.

2, No.